Red Hat GFS 6.1 -, Руководство администратора

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36 Chapter 5. Managing GFS
5.4. GFS Quota Management
File-system quotas are used to limit the amount of file-system space a user or group can
use. A user or group does not have a quota limit until one is set. GFS keeps track of the
space used by each user and group even when there are no limits in place. GFS updates
quota information in a transactional way so system crashes do not require quota usages to
be reconstructed.
To prevent a performance slowdown, a GFS node synchronizes updates to the quota file
only periodically. The "fuzzy" quota accounting can allow users or groups to slightly ex-
ceed the set limit. To minimize this, GFS dynamically reduces the synchronization period
as a "hard" quota limit is approached.
GFS uses its
gfs_quota
command to manage quotas. Other Linux quota facilities cannot
be used with GFS.
5.4.1. Setting Quotas
Two quota settings are available for each user ID (UID) or group ID (GID): a hard limit
and a warn limit .
A hard limit is the amount of space that can be used. The file system will not let the user
or group use more than that amount of disk space. A hard limit value of zero means that no
limit is enforced.
A warn limit is usually a value less than the hard limit. The file system will notify the user
or group when the warn limit is reached to warn them of the amount of space they are
using. A warn limit value of zero means that no limit is enforced.
Limits are set using the
gfs_quota
command. The command only needs to be run on a
single node where GFS is mounted.
5.4.1.1. Usage
Setting Quotas, Hard Limit
gfs_quota limit -u
User
-l
Size
-f
MountPoint
gfs_quota limit -g
Group
-l
Size
-f
MountPoint
Setting Quotas, Warn Limit
gfs_quota warn -u
User
-l
Size
-f
MountPoint
gfs_quota warn -g
Group
-l
Size
-f
MountPoint